1. Technical Field
The present disclosure relates to a power transmission device and a wireless power transmission system that wirelessly transmit electric power using electromagnetic induction between a power transmission coil and a power receiving coil.
2. Description of the Related Art
In recent years, a portable telephone device and other various kinds of mobile devices have become popular. In such mobile devices, an improvement in functionality and performance has been made and it has become possible to treat a wide variety of contents, and accordingly mobile devices need increasingly large power consumption. In a mobile device that operates with a battery with a predetermined capacity, if the power consumption thereof increases, the allowed operation time thereof decreases. A wireless power transmission system is attracting much attention as a technique to compensate for the limitation on the capacity of the battery. In the wireless power transmission system, electric power is transmitted wirelessly from a power transmission device to a power receiving device using electromagnetic induction between a power transmission coil of the power transmission device and a power receiving coil of the power receiving device. In particular, a wireless power transmission system using a resonant power transmission coil and a resonant power receiving coil is capable of maintaining a high transmission efficiency even when there is some deviation in relative position between the transmission coil and the power receiving coil, and thus this type of wireless power transmission system is expected to be used in various applications (for example, see Japanese Unexamined Patent Application Publication No. 2006-60909).